SAGA Pattern
The SAGA Pattern is an architectural approach to managing long-lived, distributed transactions in microservices. Instead of using a traditional, centralized transaction to ensure atomicity across services, a saga breaks the process into a series of local transactions. Each local transaction updates the database and publishes an event or invokes a service that triggers the next transaction in the saga.
If a step in the process fails, the saga executes compensating transactions to undo the changes made by previous steps, thereby maintaining consistency across the system.
1. Why Use the SAGA Pattern?
In a microservices architecture, distributed transactions are inherently more complex and prone to partial failures. The SAGA Pattern is particularly valuable because it:
- Ensures Data Consistency: Instead of leaving the system in an inconsistent state after a failure, compensating transactions roll back the effects of prior steps.
- Improves Resilience: By managing failures locally and compensating for them, sagas prevent cascading failures across services.
- Enables Scalability: Local transactions are easier to scale and manage compared to global transactions spanning multiple services.
- Simplifies Distributed Transactions: Sagas allow each microservice to maintain its own transaction, avoiding the complexities of a two-phase commit across distributed systems.